Certain pyrolysis liquids available from olefin pyrolysis units contain considerable styrene. At the moment, the styrene is of fuel value only, due to the difficulty in separating the styrene monomer from the copresent ethylbenzene and xylenes. Unfortunately the boiling points of styrene, ethylbenzene and xylenes are very close and conventional distillation techniques are not readily applicable. A method for extracting the styrene from these pyrolysis liquid streams would be of considerable economic importance. Applicants have discovered a method for separating styrene from these pyrolysis streams utilizing an anthracene as a separating agent.
Copending Applications Serial No. 263,218 and Serial No. 263,225, both filed Oct. 27, 1898, disclose the use of an anthracene to separate alpha olefins from internal olefins.
U.S. Pat. No. 3,052,737, issued Sep. 4, 1962, discloses reacting anthracene with vinylcyclohexene to produce an adduct which is then hydrogenated to convert the cyclohexene ring to a cyclohexane ring, followed by pyrolysis to produce vinylcyclohexane and anthracene. This reference does not suggest that anthracene would be useful in separating styrene from ethylbenzene and xylenes.